Milwaukee, Wis. — Tom Barrett, the Democratic challenger to Gov. Scott Walker (R) of Wisconsin, took a chance in Thursday night's televised debate, and came out swinging. It was without doubt his last big opportunity to persuade Wisconsin voters that kicking the incumbent governor out of office halfway through his term represents the best end to a bitter partisan battle that has engulfed the state for the past two years.

Down in the latest polls, Mr. Barrett, whose groomed image some political observers describe as "bland nice guy," adopted a confrontational posture toward Governor Walker, accusing him of divide-and-conquer governance and repeatedly reminding voters of an investigation stemming from Walker's tenure while Milwaukee County executive.

Whether it was effective won't be known until Tuesday, when voters go to the polls in the denouement of Wisconsin's long-running political saga. But Barrett's strategy was not without peril.

Barrett, who is mayor of Milwaukee, took a risk in adopting the more antagonistic tone because it runs counter to his image as a unifier, says John McAdams, a political scientist at Marquette University here. “When he starts looking harsh or aggressive, that could hurt him,” Mr. McAdams says. “An aggressive tone works for someone like [New Jersey Gov.] Chris Christie, but it’s a risky thing for Barrett.”

The debate’s fiery tone is likely to light up the respective political bases for both candidates, even if both men's performances were ultimately “a reiteration of well-known talking points,” McAdams says.

The recall election has drawn national – and even international – attention. Minutes before the debate began Thursday, the producer stepped in to inform the audience gathered at Marquette Law School that television affiliates throughout the state would broadcast the next hour live, national cable networks would periodically check in, and that the feed would be carried in real time from as far away as Japan.

Some of the far-flung interest is explained by the fact that only three sitting governors have been unseated through recalls in all of US history. And there's no denying that the stakes are high for both sides in the national arena. Republican interest groups across the US have rallied to Walker's defense, seeing his anti-union, government-shrinking policies as a bold blueprint that other governors and Congress should heed, even as labor groups have dedicated their resources behind ousting him. Wisconsin is also a battleground state in for the presidential election in the fall.

The latest poll, released Wednesday, showed Walker moving ahead – and raised the debate stakes for Barrett. The poll from Marquette Law School showed Walker at 52 percent to Barrett's 45 percent among likely voters.

One problem for Barrett is that some voters may cast their vote for Walker simply to show their distaste for the recall process itself and to signal that, despite any problems they may have with Walker’s policies, Democrats overreached.

Jim Kramers of Kenosha, Wis., says he is voting for Walker not because he is “against Barrett” but because the recall has had “a very negative impact on the state locally and nationally.” “We’ve become a laughingstock,” Mr. Kramers says of his state.

For Jeff Krien, a customer service representative in the suburb of South Milwaukee, “the recall should never have happened to begin with.” Mr. Krien says the protests that began in February 2011 “started out about [preserving] collective bargaining [rights for public-sector unions], but that hasn’t been talked about for months.”

During Thursday’s debate, Barrett did not dwell on the perceived damage of eliminating collective bargaining rights, but instead framed the issue as an example of Walker’s “divide and conquer strategy” in trying to transform Wisconsin into the “capital” of the tea party movement.

“You wanted to pit people against each other because that’s the way you operate, and you wanted to use a crisis [involving collective bargaining] to do that,” he told Walker.

Walker insisted, as he has in the past, that reforms were needed to address the state’s $3.6 billion budget deficit he inherited, and that he did it without raising taxes or wholesale job cuts.

“The mayor has a moral obligation to tell people what exactly he would have done differently … the mayor doesn’t have a plan and all he has is attacking me,” Walker said.

Barrett often addressed Walker directly, and he returned frequently to an ongoing investigation into Walker’s previous tenure as the Milwaukee County executive, involving allegations that workers campaigned on county time and embezzled money from veterans groups. The so-called “John Doe” ethics investigation has not targeted Walker for wrongdoing, but he has transferred about $160,000 from his campaign to a legal defense fund, which, according to state law, is lawful only if the campaign gets prior approval from donors.

Walker has so far declined to say which contributors gave their blessing.

“This is all about trust,” Barrett said before turning to Walker: “Tell us who is paying your legal defense fund … you owe it to the people of this state.”

Later, Barrett hammered Walker for a television commercial that shows a blurred image of a 2-year-old who spent almost a week in intensive care after being severely beaten. The aim of the ad was to criticize Milwaukee’s track record on preventing violent crime.

“He is running a commercial showing a picture of a dead baby. This is Willie Horton stuff," Barrett said to Walker, referring to a crime-related ad in the 1988 presidential campaign, widely seen as inflammatory, that proved devastating to Democrat Michael Dukakis. "The person who killed that baby was arrested by Milwaukee police.… You should be ashamed,” he said.

Walker defended the ad, saying Barrett campaigned in the primary on his work to reduce the violent crime rate. “I think if it was worth to say that people should vote for you in the primary because it had gone down, the same question is completely legitimate in reverse. Violent crime has gone up, sadly,” Walker said.

The Marquette poll that shows Walker up by seven percentage points was conducted May 23-26, before the first gubernatorial debate. However, “if the Marquette poll is accurate, it’s going to be tough for Barrett,” McAdams says.

“There’s a very small number of undecided voters, so there’s not a lot of people out there to be moved,” he says.

One such resolute voter is Karen Stardy, a farmer from Union Grove. Earlier in the day, while manning her booth at a farmer’s market in South Milwaukee, Ms. Stardy said her disgust was not necessarily with Barrett but with how the recall election is dividing her community but not offering real solutions to turning the economy around.

“There’s arguments all over the place. It’s like, nobody’s really right and nobody’s really wrong,” she said. “I’d rather not see people arguing over politics. We have to tough it out. There’s no instant solution to the problems that we’ve got.”